川西甘孜-理塘结合带洋岛型玄武岩地球化学、年代学特征及其地质意义

doi:10.13686/j.cnki.dzyzy.2021.06.003

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摘要甘孜-理塘结合带作为三江特提斯造山带与松潘-甘孜造山带的重要组成部分，发育大量的洋岛-海山岩石组合，洋岛玄武岩的存在标志着洋盆已发育成熟的洋壳.木里地区的洋岛-海山岩石组合由"基性火山岩+碳酸盐岩"构成，对基性火山岩的地球化学特征分析表明：基性火山岩SiO₂含量为40.17%~49.19%，TiO₂含量1.77%~4.86%，Al₂O₃含量9.67%~15.39%，MgO含量3.85%~17.75%，全碱含量（K₂O+Na₂O）0.87%~6.33%，属碱性玄武岩系列.稀土总量∑REE值较高，为106.21×10^-6~378.83×10^-6，（La/Yb）_N比值为9.23~39.41，为轻稀土富集型，Eu、Ce无异常，配分模式为右倾型.微量元素表现出大离子亲石元素Rb、Ba、Th、K富集，而亏损高场强元素Nb、Zr.稀土元素及微量元素特征与标准洋岛型玄武岩相近，源区为软流圈地幔石榴石橄榄岩，且部分经历了岩浆结晶分异，形成于洋岛台地环境.玄武岩的锆石U-Pb定年结果为218.96~221.71 Ma，表明洋岛型玄武岩形成于晚三叠世中期.

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关键词 ：地球化学, 地质年代学, 洋岛型玄武岩, 甘孜-理塘结合带, 晚三叠世, 四川省

Abstract：A large number of oceanic island-seamount rock assemblages are developed in Ganze-Litang junction zone-an important part of Sanjiang Tethyan Orogen and Songpan-Ganze Orogen. The existence of oceanic island basalts (OIB) indicates that mature oceanic crust has developed in the ocean basin. The oceanic island-seamount rock assemblages in Muli area are composed of basic volcanic rocks and carbonate rocks. The geochemical analysis of basic volcanic rocks shows the SiO₂ content of 40.17%-49.19%, TiO₂ 1.77%-4.86%, Al₂O₃ 9.67%-15.39%, MgO 3.85%-17.75% and total alkali (K₂O+Na₂O) 0.87%-6.33%, respectively, belonging to alkali basalt series. The basalts are characterized by high ∑REE (106.21×10^-6-378.83×10^-6), (La/Yb)_N of 9.23-39.41, LREEs enrichment, without Eu and Ce anomalies, right-dipping distribution patterns, enriched LILEs (Rb, Ba, Th and K), and depleted HFSEs (Nb and Zr). The characteristics of REEs and trace elements are similar to those of standard OIBs, with the provenance of garnet peridotite from asthenosphere mantle, some undergoing magmatic crystallization differentiation and forming in oceanic island platform environment. The zircon U-Pb dating result of basalts (218.96-221.71 Ma) reveals that the OIBs were formed in middle Late Triassic.

Key words： geochemistry geochronology oceanic island basalt (OIB) Garze-Litang junction zone Late Triassic Sichuan Province

收稿日期: 2020-07-14

PACS:	P595
	P597

基金资助:中国地质调查局区域地质矿产调查项目"四川1：5万东朗乡等6幅区域地质矿产调查"（1212011220384）.

作者简介: 罗绍强(1985-),男,硕士,工程师,主要从事区域地质调查工作,通信地址四川省绵阳市涪城区剑门路西段88号,E-mail//277912663@qq.com

引用本文:

罗绍强, 唐华, 肖进, 刘大明, 代伦. 川西甘孜-理塘结合带洋岛型玄武岩地球化学、年代学特征及其地质意义[J]. 地质与资源, 2021, 30(6): 656-665.
LUO Shao-qiang, TANG Hua, XIAO jin, LIU Da-ming, DAI Lun. OCEANIC ISLAND BASALTS IN GARZE-LITANG JUNCTION ZONE, WESTERN SICHUAN PROVINCE: Geochemistry, Geochronology and Geological Implication. GEOLOGY AND RESOURCES, 2021, 30(6): 656-665.

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[1]	许志琴, 侯立玮, 王宗秀, 等. 中国松潘-甘孜造山带的造山过程[M]. 北京:地质出版社, 1992:170-172. Xu Z Q, Hou L W, Wang Z X, et al. Orogenic processes of the Songpan-Ganze orogenic belt of China[M]. Beijing:Geological Publishing House, 1992:170-172. (in Chinese)
[2]	邹光富, 侯立玮, 尹显科. 甘孜-理塘蛇绿混杂岩带特征及其构造意义[J]. 四川地质学报, 1994, 14(1):17-24. Zou G F, Hou L W, Yin X K. Characteristics of Garze-Litang ophiolite melange zone and its tectonic implication[J]. Acta Geologica Sichuan, 1994, 14(1):17-24.
[3]	蔡雄飞, 蔡海磊, 刘德民. 造山带洋岛混杂岩系地层序列和研究意义[J]. 海洋地质动态, 2006, 22(4):9-11. Cai X F, Cai H L, Liu D M. Stratigraphic sequences of mixtite series in oceanic islands of orogenic belts and the significance of study[J]. Marine Geology Letters, 2006, 22(4):9-11.
[4]	严松涛, 段阳海, 谭昌海, 等. 甘孜-理塘蛇绿混杂岩带中三叠世洋岛型岩石组合的识别及其构造意义——来自岩石学、地球化学和年代学证据[J]. 地球学报, 2019, 40(6):816-826. Yan S T, Duan Y H, Tan C H, et al. Identification of the Middle Triassic Ocean Island rock association in the Garze-Litang ophiolite mélange zone and its tectonic significance:Constraints from petrology, geochemistry and geochronology[J]. Acta Geoscientica Sinica, 2019, 40(6):816-826.
[5]	王立全, 潘桂堂, 丁俊, 等. 1:150万青藏高原及邻区地质图及说明书[M]. 北京:地质出版社, 2013:114. Wang L Q, Pan G T, Ding J, et al. Geological maps and specifications of the Tibetan plateau and its adjacent areas[M]. Beijing:Geological Publishing House, 2013:114. (in Chinese)
[6]	曾云, 贺金良, 王秀京, 等. 四川省成矿区带划分及区域成矿规律[M]. 北京:科学出版社, 2015:9-10. Zeng Y, He J L, Wang X J, et al. Zoning of metallogenic belt and regional metallogenic regularity in Sichuan Province[M]. Beijing:Science Press, 2015:9-10.
[7]	侯可军, 李延河, 田有荣. LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J]. 矿床地质, 2009, 28(4):481-492. Hou K J, Li Y H, Tian Y R. In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS[J]. Mineral Deposits, 2009, 28(4):481-492.
[8]	马涛, 张健, 王晓青, 等. 西藏萨嘎二叠纪OIB型火山岩岩石地球化学特征及成因分析[J]. 西北地质, 2017, 50(3):22-35. Ma T, Zhang J, Wang X Q, et al. Geochemical characteristics and genesis of Permian OIB-type volcanic rocks in Saga region, Tibet[J]. Northwestern Geology, 2017, 50(3):22-35.
[9]	Wilkinson J F G. The genesis of mid-ocean ridge basalt[J]. Earth-Science Reviews, 1982, 18(1):1-57.
[10]	邓晋福. 岩石相平衡与岩石成因[M]. 武汉:武汉地质学院出版社, 1987:24-31. Deng J F. Lithofacies equilibrium and petrogenesis[M]. Wuhan:China University of Geoscience Press, 1987:24-31. (in Chinese)
[11]	Winchester J A, Floyd P A. Geochemical discrimination of different magma series and their differentiation products using immobile elements[J]. Chemical Geology, 1977, 20:325-343.
[12]	李运冬, 刘小玉. 青海热水地区晚三叠世火山岩地球化学特征及构造环境[J]. 西北地质, 2014, 47(3):14-25. Li Y D, Liu X Y. Geochemistry and tectonic setting of late Triassic volcanic rocks in Reshui area, Qinghai[J]. Northwestern Geology, 2014, 47(3):14-25.
[13]	Weaver B L. The origin of ocean island basalt end-member compositions:Trace element and isotopic constraints[J]. Earth and Planetary Science Letters, 1991, 104(2/4):381-397.
[14]	Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes[C]//Saunders A D, Norry M J. Magmatism in the Ocean Basins. Geological Society, London, Special Publications, 1989, 42(1):313-345.
[15]	徐义刚. 地幔柱构造、大火成岩省及其地质效应[J]. 地学前缘, 2002, 9(4):341-353. Xu Y G. Mantle plumes, large igneous provinces and their geologic consequences[J]. Earth Science Frontiers, 2002, 9(4):341-353.
[16]	Pearce J A, Cann J R. Tectonic setting of basic volcanic rocks determined using trace element analyses[J]. Earth and Planetary Science Letters, 1973, 19(2):290-300.
[17]	Le Roex A P, Dick H J B, Erlank A J, et al. Geochemistry, mineralogy and petrogenesis of lavas erupted along the Southwest Indian Ridge between the Bouvet triple junction and 11 degrees east[J]. Journal of Petrology, 1983, 24(3):267-318.
[18]	Weaver B L. Trace element evidence for the origin of ocean-island basalts[J]. Geology, 1991, 19(2):123-126.
[19]	Viccaro M, Cristofolini R. Nature of mantle heterogeneity and its role in the short-term geochemical and volcanological evolution of Mt. Etna (Italy)[J]. Lithos, 2008, 105(3/4):272-288.
[20]	Helo C, Hegner E, Kröner A, et al. Geochemical signature of Paleozoic accretionary complexes of the Central Asian Orogenic Belt in South Mongolia:Constraints on arc environments and crustal growth[J]. Chemical Geology, 2006, 227(3/4):236-257.
[21]	韩兆诣. 甘孜-理塘结合带南段玄武岩特征及构造意义[D]. 绵阳:西南科技大学, 2015. Han Z Y. Basalt characteristics and tectonic significance in the Southern of Garze-Litang Suture Zone[D]. Minyang:Southwest University of Science and Technology, 2015.
[22]	鄢圣武,白宪洲,秦宇龙,等. 四川昭觉-美姑地区峨眉山玄武岩古火山机构的发现及其喷发旋回的确定[J]. 中国地质, 2021, 48(2):536-548. Yan S W, Bai X Z, Qin Y L, et al. Discovery of paleo-volcanic edifice and determination of its eruptive circles of Emeishan basalt in Zhaojue-Meigu area, Sichuan Province[J]. Geology in China, 2021, 48(2):536-548.
[23]	谢纪海,胡正祥,毛新武,等. 鄂北大洪山晋宁期MORB-like玄武岩的识别与洋内俯冲作用[J]. 中国地质, 2019, 46(6):1496-1511. Xie J H, Hu Z X, Mao X W, et al. The discrimination of Jinningian MORB-like basalt and intra-oceanic subduction in the Dahongshan area, northern Hubei[J]. Geology in China, 2019, 46(6):1496-1511.
[24]	Pearce J A, Norry M J. Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks[J]. Contributions to Mineralogy and Petrology, 1979, 69(1):33-47.
[25]	Mullen E D. MnO/TiO2/P2O5:A minor element discriminant for basaltic rocks of oceanic environments and its implications for petrogenesis[J]. Earth and Planetary Science Letters, 1983, 62(1):53-62.
[26]	Vermeesch P. Tectonic discrimination diagrams revisited[J]. Geochemistry, Geophysics, Geosystems, 2006, 7(6):Q06017.
[27]	潘桂棠, 陈智梁, 李兴振, 等. 东特提斯地质构造形成演化[M]. 北京:地质出版社, 1997:69-107. Pan G T, Chen Z L, Li X Z, et al. Geological-Tectonic evolution in the Eastern Tethys[M]. Beijing:Geological Publishing House, 1997:69-107. (in Chinese)
[28]	张世涛, 冯庆来, 王义昭. 甘孜-理塘构造带泥盆系的深水沉积[J]. 地质科技情报, 2000, 19(3):17-20. Zhang S T, Feng Q L, Wang Y Z. Devonian deep-water sediments in Garze-Litang tectonic belt[J]. Geological Science and Technology Information, 2000, 19(3):17-20.
[29]	杨文强, 冯庆来, 刘桂春. 滇西北甘孜-理塘构造带放射虫地层、硅质岩地球化学及其构造古地理意义[J]. 地质学报, 2010, 84(1):78-89. Yang W Q, Feng Q L, Liu G C. Radiolarian fauna and geochemical characters of the cherts from Garze-Litang tectonic belt and its tectono-paleogeographic significance[J]. Acta Geologica Sinica, 2010, 84(1):78-89.